There is one personality test that is far and away more scientifically valid than any of the others: the “Big Five.”

The Big Five evaluates personality by measuring—as the name suggests—five personality traits: openness to experience, conscientiousness, extraversion, agreeableness, and neuroticism, each on a continuous scale. Studies have shown it that it effectively predicts behavior, and the test is often used in academic psychological personality research. People who score higher in conscientiousness tend to work harder, for example, while more neurotic personalities are more prone to anxiety and depression.

Despite its scientific validity, and even with the contemporary fascination with personality tests, the Big Five is relatively unpopular outside of academia. A recent FiveThirtyEight article on the subject suggested that personality scientists haven’t effectively marketed the one credible personality test.

But there are serious concerns not just with the marketing of the test, but with how it’s presented to a public audience. Despite the scientific rigor around the Big Five in academia, many online versions of the test are designed to give sexist results.